The present invention relates to apparatus for processing exposed photographic films and containers for exposed photographic films. More particularly, the invention relates to improvements in apparatus, known as presplicers, which are utilized in photographic processing laboratories to unite a large number of exposed customer films into a continuous web which is ready for transport through a developing machine.
Photographic roll films which are delivered or mailed to a processing laboratory for development and the making of prints are usually spliced together to form a long web often having a length in the range of several hundred meters. The web is coiled onto a reel and is thereupon advanced through a developing machine. As a rule, the developed web is thereupon advanced through a printing or copying machine which makes reproductions of some or all film frames. The prints are inserted into envelopes, together with the corresponding films (which can be subdivided into sections each consisting of several frames), and the envelopes are mailed to or picked up by the dealers or directly by the customers.
Exposed photographic roll films are shipped or delivered to a processing laboratory together with the corresponding containers, e.g., in the so-called "110 cassettes." The containers are opened in a darkroom, the films are removed from the opened containers, the removed films are transported to a trimming and splicing station where the ends of successive films are trimmed and united by adhesive-coated bands, and the resulting web is convoluted onto a reel preparatory to transport through the developing machine. The opening of containers by hand or by means of a manually operated device is a tedious and time-consuming procedure, especially since the opening of containers must take place in a darkroom. This often results in damage to exposed films due to carelessness or ineptness of the attendants. It was therefore proposed to employ an automatic opening device which cracks successive containers in a darkroom and removes the exposed films in a position in which the films are ready for transport to the trimming and splicing station. The just mentioned automatic opening device also exhibits several drawbacks, i.e., it is rather complex because each of a series of successively admitted containers must or should be cracked open at the same locus, and the device must comprise means which invariably reaches the exposed film in the opened container and transports the film in a predictable and reproducible way. As a rule, the cracking of containers (which normally consist of synthetic plastic material) is accompanied by chipping of the material of the containers whereby the fragments (some of which are rather large and many of which have sharp edges) are likely to damage or affect the operation of sensitive parts in the darkroom. Moreover, such fragments are likely to scratch or otherwise deface the exposed films.
The commonly owned U.S. Pat. No. 3,921,878 granted Nov. 25, 1975 to Zangenfeind discloses an apparatus which can remove exposed films without necessitating any opening or breaking of the containers. The film is withdrawn by the customary backing strip whose leader is expelled by a pusher which enters the container by way of a window in the back of the exposure opening and pushes the leader of the backing strip through the exposure opening. The patented apparatus can be used with advantage for removal of exposed films from "110 cassettes". In most instances, containers of the just described type are received by the processing laboratory in a condition which enables the patented apparatus to remove the exposed films without opening the respective containers. However, it happens from time to time that the exposed film, as well as the backing strip, is fully convoluted onto the takeup spool in the interior of the container. This renders it impossible to remove the exposed film without opening the container. Such situation will arise when the camera in which the film was exposed is not provided with an overload clutch which becomes effective when the user wishes to advance the film subsequent to completion of exposure of the last film frame in the container. The trailing end of the backing strip is then detached from the supply spool and is advanced beyond the aforementioned window so that the pusher is unable to expel the backing strip through the exposure opening. It has been found that between 10 to 20 percent of all containers which are delivered or shipped to a processing laboratory are not in a condition to allow for removal of exposed film without breaking the container. In other words, even if the processing laboratory is equipped with an apparatus of the type disclosed in the aforementioned patent to Zangenfeind, it is still necessary to forcibly open a relatively large number of containers in order to gain access to the exposed photographic roll films therein.